Most people have skin or hair imperfections. The cosmetic impact of hair and skin imperfections can be ameliorated with the use of an appropriate product. Selection of appropriate product for any given individual begins with an evaluation of the person's skin or hair (skin of the scalp can be used for such an evaluation).
Although various methods for measuring properties of skin or hair may be known, measurement can be more difficult to obtain on same parts of the body than on others. Thus, for example, it is not difficult to apply a hydration measurement device to areas of the body such as arms or cheeks because there is generally far less interference from hairs. Further, such areas generally offer a very shallow curvature and are compliant, readily conforming to the sensing surface of the hydration measurement device with little force. However, it is often a challenge to apply such devices to the skin in the scalp area because of interference from hair. That is, hair can be trapped between a sensor and the skin of the scalp, for example. Hair entrapment reduces contact between the skin of the scalp and the sensor resulting in an erroneous hydration measurement. Also, the contour of the scalp is such that a conventional hydration sensor cannot be readily applied due to curvature of the scalp as well as the relative non-compliance of the scalp and underlying tissue. This non-contact and excessive force when taking a hydration measurement also introduce error.
In the recommendation of appropriate hair care products in particular, it would be highly beneficial to obtain evaluation and measurements (e.g., hydration value measurements) from the skin of the scalp area. For example, a person who has imperfections of the skin of the scalp (e.g., exhibiting skin dryness, redness, dandruff) often requires different product from a person having skin of the scalp in generally good condition. However, it is not easy to obtain measurements readily on skin of the scalp both because of the contours of the head as well as interference of hair follicles typically present there. That is, hair trapped between the active surface of the hydration measurement device and the skin of the scalp alters hydration measurements as noted above.
Applicants have now devised a device comprising a central housing, a hydration meter (sensor) supported within the housing and projecting from at least one side of the housing, the end of which hydration meter has a surface evaluation area whose external surface has an aspect ratio wherein the width is greater than the length (>1:1), defining, for example, a rectangle. Preferably, ratio of width to length is >1.3:1, more preferably ≧2:1 and more preferably ≧3:1. While there is no clear upper limit, higher aspect ratios have small active area for the length, and the curvature of the scalp can become more problematic for long sensors (e.g., because the ends don't touch the skin and don't participate in the measurement which can show that result). Generally, it is desirable to have a sensor length that allows the edges of the sensor to touch the scalp without applying so much force to the skin of the scalp that the force alters the fluid distribution in the skin and skews the measurement. Assuming a rigid sensor (which is not necessarily the case), sensors should preferably be no longer than about 1.3 cm, preferably no longer than 1.2 cm. A more flexible/compliant sensor could be a bit longer (narrower). A narrower sensor is also more favorable (whether using rigid or flexible sensor) because it is less influenced by hair.
The external surface may also be in the form of an ellipse (i.e., wherein the aspect ratio of major axis, i.e., the width, to minor axis i.e., the height, is again >1:1, preferably >1.3:1, more preferably ≧2:1 and more preferably ≧3:1). Indeed, as long as the width is greater than the length or the height, the shape can be rectangular, elliptical, obround, trapezoidal or any shape meeting such definition. As noted above, sensor (especially rigid sensor) should ideally be no longer than about 1.3 cm.
Preferably, the shape is what we refer to as oblong. By oblong can be meant, for example, purely rectangular (straight edges on all sides); or rectangular, but with side edges which define the length/height rounded outward rather than straight, a term we define as obround (see FIG. 6). Such oblong-shape external surface or shape (e.g., obround) has been found particularly suitable for pressing the surface evaluation area of the hydration meter against the skin of the scalp to make optimal contact with skin (e.g., it conforms readily to the curvature of the skull) and most readily obtain hydration values. Further, because camera and sensor need not be co-located (co-location drives conformity with camera lens which lens, for example, is typically circular), such preferred oblong shape can be readily used.
The housing on the device also comprises an electrical wire or optical cord, particularly a USB cable terminating in a USB port which plugs into a computer and accesses programs. The program, for example, makes comparisons of pictures taken by the camera on the device to pictures stored in the program, and/or to stored information gathered relating to hydration values. This is described in further detail below.
Finally, in addition to the hydration meter or sensor (which itself comprises a transducer which changes its electrical capacitance depending on skin hydration; and an interface circuit that measures changes in capacitance and thereby hydration) supported by and projecting from at least one end of a housing (as indicated, the end of said meter terminates in an evaluation area with aspect ratio where width is greater than length or height and is shaped for best contacting skin along the curvature of the scalp); and to a cable terminating in a USB port or other means for transmitting data; the housing further contains a camera (also supported by and projecting from a separate end on the same housing) for capturing and electronically recording images of an area of skin or hair. The captured image is compared (either in software via digital means or by a person) to other images stored in the computer and, based on both an evaluation of computer images done by the computer program and/or evaluation of measured hydration values (or both), the consumer is advised about the state of the scalp so that a preferred cosmetic product can be recommended.
Thus, the device of the invention comprises a housing with (1) one end terminating in a hydration meter or sensor (comprising transducer and interface circuit for picking up and measuring hydration) having surface evaluation area with defined aspect ratio; (2) a separate second end comprising a camera and (3) a separate end terminating in a USB port or other means for transmitting data. Applicant is thus able to effectively measure multiple parameters (e.g., hydration measurement, captured images) to help quantify or define skin (especially skin of the scalp area) or hair condition. Use of multiple parameters (although each can be used alone) makes recommendation of a product highly tailored, targeted and effective.
Applicant has filed an application on a previous device comprising a housing with a hydration meter and a plurality of light emitting diodes. However, the present device is an improvement over that device in several respects. First, based on the shape of the external evaluation surface of the hydration meter, the meter can be readily and easily applied to the contours of the scalp. Further, the hydration meter and camera for capturing images on the scalp are placed on separate extensions of the same device allowing for optimal performance of the hydration meter and camera. As noted above, the separation of the camera and sensor permits use of, for example, an oblong sensor because the sensor need not conform to shape of camera opening. This, in turn, allows sensor to be placed more readily along the curvature of the scalp and to provide more accurate hydration measurements.